Quorum-sensing regulation of adhesion in Serratia marcescens MG1 is surface dependent
Quorum-sensing regulation of adhesion in Serratia marcescens MG1 is surface dependent
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DOI：
10.1128/jb.01582-06
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发表时间：
2007-04-01
影响因子：
3.2
通讯作者：
Kjelleberg, Staffan
中科院分区：
文献类型：
--
作者：
Labbate, Maurizio;Zhu, Hua;Kjelleberg, Staffan
粘质沙雷氏菌是一种机会性病原体，也是眼部感染的主要原因。在之前对粘质沙门氏菌 MG1 的研究中，我们发现生物膜的成熟和脱落受到基于 N-酰基高丝氨酸内酯 (AHL) 的群体感应 (QS) 的调节。由于粘附在启动生物膜形成和感染中的重要性，本研究的主要目标是确定 QS 对于非生物和生物表面的粘附是否重要，通过确定亲水组织培养板和人角膜上皮 (HCE) 细胞的附着程度进行评估。我们的结果表明，虽然对非生物表面的粘附受到 AHL 调节，但对 HCE 细胞生物表面的粘附则不受 AHL 调节。 I 型菌毛被确定为非 QS 介导的生物 HCE 细胞表面附着的关键粘附素，但在非生物表面的粘附中不起任何作用。虽然我们无法鉴定出附着在非生物表面所必需的单一 QS 调节的粘附素，但鉴定出了四种参与非生物表面粘附的 AHL 调节基因。有趣的是，其中两个基因 bsmA 和 bsmB 也被证明以非 QS 控制的方式参与生物表面的粘附。因此，这两个基因的表达似乎是由除 QS 系统以外的调节因子共同控制的，以介导 HCE 细胞的附着。我们还发现粘质链球菌中的 QS 调节其他潜在的细胞表面粘附素，包括胞外多糖和外膜蛋白 OmpX。我们得出的结论是，粘质沙雷氏菌 MG1 在附着于生物和非生物表面时利用不同的调节系统和粘附素，并且 QS 是粘附于非生物表面的主要调节途径，但不是粘附于生物表面的主要调节途径。
Serratia marcescens is an opportunistic pathogen and a major cause of ocular infections. In previous studies of S. marcescens MG1, we showed that biofilm maturation and sloughing were regulated by N-acyl homoserine lactone (AHL)-based quorum sensing (QS). Because of the importance of adhesion in initiating biofilm formation and infection, the primary goal of this study was to determine whether QS is important in adhesion to both abiotic and biotic surfaces, as assessed by determining the degree of attachment to hydrophilic tissue culture plates and human corneal epithelial (HCE) cells. Our results demonstrate that while adhesion to the abiotic surface was AHL regulated, adhesion to the HCE cell biotic surface was not. Type I fimbriae were identified as the critical adhesin for non-QS-mediated attachment to the biotic HCE cell surface but played no role in adhesion to the abiotic surface. While we were not able to identify a single QS-regulated adhesin essential for attachment to the abiotic surface, four AHL-regulated genes involved in adhesion to the abiotic surface were identified. Interestingly, two of these genes, bsmA and bsmB, were also shown to be involved in adhesion to the biotic surface in a non-QS-controlled fashion. Therefore, the expression of these two genes appears to be cocontrolled by regulators other than the QS system for mediation of attachment to HCE cells. We also found that QS in S. marcescens regulates other potential cell surface adhesins, including exopolysaccharide and the outer membrane protein OmpX. We concluded that S. marcescens MG1 utilizes different regulatory systems and adhesins in attachment to biotic and abiotic surfaces and that QS is a main regulatory pathway in adhesion to an abiotic surface but not in adhesion to a biotic surface.